Supplement to the Index of Middle English verse / Rossell Hope Robbins, John L. Cutler. (OCLC #897386804)
The title page of this resource gave me pause… who are the authors? Robbins and Cutler or Brown and Robbins?
The preface to this volume (signed with initials R.H.R. and J.L.C.) indicates that this supplement is the result of their joint research. R.H.R. also mentions in the preface that Carleton Brown not only honored him by collaboration on the Index, but also by solemnizing his marriage. From this info in the preface, I was able to sort out who was responsible for what.